To condition the temperature and humidity in a room or enclosure from a central heating and cooling unit, it is typical to mount a vent or distributor for inflow of air from the unit and a return duct to draw air from the room back to the unit. An important factor in designing the inlet vent is to distribute the inflowing air as uniformly as possible throughout the room and in a flow that attempts to minimize drafts.
Other considerations must be taken into account when the room to be conditioned is in a security area, such as a jail cell. For example, in a jail cell, a concern arises that the prisoner may vandalize units or otherwise alter their normal function. Several attempts have been made to provide ventilation units for security areas such as U.S. Pat. No. 4,505,189 to Morris et al. which discloses a vandal resistant and tamper-proof plenum vacuum chamber security airflow adjustment device, U.S. Pat. No. 3,722,152 to Schlatter et al. which discloses a portable jail cell and U.S. Pat. No. 4,970,834 to Polson which discloses a detention facility which has a mesh ceiling through which heating and ventilation air passes. A need exists, however, for a better design for a high security area.